'Door' in the Bible

Verily, verily, I say unto you, He that entereth not by the door into the fold of the sheep, but climbeth up some other way, the same is a thief and a robber.

But he that entereth in by the door is the shepherd of the sheep.

Jesus therefore said unto them again, Verily, verily, I say unto you, I am the door of the sheep.

I am the door; by me if any man enter in, he shall be saved, and shall go in and go out, and shall find pasture.

but Peter was standing at the door without. So the other disciple, who was known unto the high priest, went out and spake unto her that kept the door, and brought in Peter.

The maid therefore that kept the door saith unto Peter, Art thou also one of this man's disciples? He saith, I am not.